Water is not hot or too hot.

If the power supply is ok, turn the temperature control knob clockwise as far as possible. Wait for 15 minutes and check the water temperature.

If the water is still not hot; Turn the temperature control knob 3-4 times clockwise and counter clockwise and then turn the control knob clockwise as far as possible Wait for 15 minutes and check the water temperature.

If the water is still not hot, there may be problem with the internal heating mechanism or thermostat contacts are stuck.